Control for fire-shutters.



P. F. KRUG.

CONTROL FOR FIRE SHUTTERS.

APPLICATION FILED 0CT.26, 1914.

Patented Apr. 4, 1916.

I fizz/Emma:

PHILIP F. KRUG, OF NEW YORK, N. Y.

CONTROL For. FIR-E-SI-IUTTERS.

Specification of Letters Patent.

7 Patented Apr. 4, 1916.

Original application filed July 13, 1914, Serial No. 850,535. Dividedand this application filed October 26,

i 1914. Serial No. 868,681.

New York, have invented certain new and useful Improvements in Controlfor Fire- Shutters, of which the following is a specification.

My invention relates in general* to a moving picture machine andparticularly relates to a control for automatically opening the fireshutter of such a machine when the rotary parts of the film feedingmechanism have reached a preset speed.

This application constitutes a division of my application, Serial No.850,535, filed July 13, 1914.

One of the objects of my invention is to provide a simple andautomatically controlled device of the above indicated character, whichwill be positive in its action in opening the shutter and which willpermit the prompt and automatic closing of the shutter when the speed ofthe film feeding mechanism has fallen below the preset speed at whichthe device may be safely operated.

I attain the above outlined objects broadly by providing a rotary memberhaving diametrically movable weighted parts nor-' mally held inretracted position by a suitable spring and adapted to be actuated bythe centrifugal force of rotation of the member to move against theresistance of the spring and into a frictional clutching engagement witha shutter actuating part.

Various other objects and advantages of the invention will be in partobvious from an inspection of the accompanying'drawings and in part willbe more fully set forth in the following particular description of oneform of mechanism embodying the invention and it also consists incertain new and novel features of construction and combination of partshereinafter set forth and claimed.

Referring to the accompanying drawings: Figure 1 shows a fragmentaryportion of a moving picture machine head in side elevation with apreferred embodiment of my invention attached thereto; and Figs. 2 and 3are respectively longitudinal and transverse sectional views through theshutter control shown in F ig.'1.

shaft 13 has a feed sprocket 14 mounted thereon and driven directly fromthe gear wheel 12 by means of a relatively small gear wheel 15. The film16 is continuously fed into the upper loop 17 from which it passesthrough the usual frictional holding means 18 about the picture aperturelt) such as is usual in devices of this character. A weighted fireshutter 40 has its upper edge pivoted to the machine in rear of thepicture aperture 19 and is actuated by means of a link 41 attached tothe outer rim 42 of a shutter control "43 mounted on the feed sprocketshaft 13. This control includes a disk 44 keyed to the shaft 13 andconcentrically mounted within the rim 42 of an enclosing cylindricalshell mounted loosely on the shaft 13. The disk has a plurality ofdiametrically disposed recesses 45 open ing to the periphery thereof,which recesses each contain a heavy sliding block 46 movable out of therecess under contrifugal force of the rotating shaft 13. Disposedbetween the periphery of the disk 44 and the inner surface of the rim 42is a single coiled spring 47, the tendency of which spring is to wrapitself closely about the periphery of r the disk bearing on the blocks46. It has been found in practice that the spring need have but a singlecoil even less than 360 and is preferably made very light.

In operation, and with the parts in the position shown in Fig. 1, theactuation of the shaft 13 causes the weights 46 in the shutter control43 to move outward under centrifugal force and act on the coil spring 47to bind the same against the rim 42 causing the same to rotate over anarc and act upon-the link 41 to move the shutter into open position.Reducing the speed of rotation of the shaft 13 correspondingly reducesthe tension on the weights 46, permits the spring 47 to contract out ofengagement with'the rim 42, thus allowing the shutter 40 to fall bygravity into its closing positlon intercepting the passage of lightthrough the machine as is usual with 7 by the spring 47 which mayreadily be replaced when Worn. By varying the length of this spring itsclutching action may be accurately adjusted so as to become operative atany particular speed of the film feeding mechanism.

The device. may be readily and cheaply constructed as there is nonecessity of refined milling or interfitting of parts, it being merelynecessary to roughly drill the recesses 45 to produce a guide for theblocks 46.

While I have shown and described, and have pointed out in the annexedclaim, certain novel features of my invention, it will be understoodthat various omissions, substitutions and changes in the form anddetails of the device illustrated and in its operation may be made bythose skilled in the art Without departing from the spirit of theinvention.

Having thus described my invention, I claim In a moving-picture machine,a fire shutter control comprising a rotary disk having a plurality ofdiametrically disposed re cesses in the periphery thereof, a pluralityof Weighted blocks, each having a sliding fit in one of said recessesand movable out- Wardly under the centrifugal force of the rotatingdisk, a band surrounding the periphery of the disk and having a slippingfit thereon, guiding means engaging the band.

to prevent transverse movement thereof, a spring coiled about the diskand normally disposed with all portions thereof engaging the disk andspaced Within the band, the diameter of said spring adapted to beenlarged by the centrifugal action of the Weighted blocks thereby tobring the spring into frictional engagement with the band and a shutteractuating member operatively I 'Copies of this patent may be obtainedfor five cents each, by addressing the Commissioner of. Patent!-Washington, D. C.

